1. Field of the Invention
The present invention relates to polymers, and more particularly to novel chemical compounds pertaining to polymer products of isocyanates, namely to polyurethane urea acyl semicarbazides.
The compounds of the present invention may be used in restorative surgery for preparing biodegradable alloimplants intended to remove the defects of organs and tissues.
At present, alloimplants made from biodegradable synthetic polymer materials are usually used for such purposes. After removing the tissue defects, such alloimplants should, in the course of time, provide for the regeneration of the tissues and then be removed from the organism in the form of biodegradation products. At present, the biodegradation of the alloimplants made from synthetic polymer materials is provided for and controlled by introducing the required number of labile links in the main chain of a polymer. However, it is rather difficult to precisely control the time of biodegradation in this case, because the enzymous composition of the tissues is neglected.
Attempts have been made to control the biodegradation time of the polymer materials by increasing the concentration of labile links in the main chain of a polymer by changing the chemical nature of the side groups of the polymer chain as well as by controlling the hydrophilic-and-hydrophobic balance of the polymer macromolecules.
Rather prospective in today's medicine is the use of compounds based on polyurethanes whose chemical and physical properties can be goal-orientedly varied in a wide range.
For example, known in the art is a cross-linked formed polyurethane (see French Patent No 2,318,183) which is prepared in the result of interaction between water and polyurethane prepolymer blocked by isocyanate. However, the destruction of said foamed polyurethane occurs as a result of hydrolysis of an ester group in the main chain of the initial prepolymer, i.e. the enzymous properties of the tissues are ignored.
Thus, the above facts prove that the problem has not been adequately solved up till now.